<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<script>
    function RunYear(){
        var flag = false;
        if(year % 4 == 0 && year % 100 !=0 ||year%400==0){
            flag = true;
        }
        return flag;
    }
    var year = prompt('输入年份');
    console.log(RunYear(year));
</script>
<body>
    
</body>
</html>